The proposed research can be divided into three catagories. These are: (a) studies of the regioselectivity, reversibility and mechanism of the asymmetric addition reaction of chiral sulfinylallyl anions with ambident electrophiles, enones and enimines, (b) synthetic applications of the above reaction as illustrating by the asymmetric total syntheses of (+)-pentalenene, (+)-pentalenolactone, deoxypentalenylglucuron and heterocyclic compounds and (c) total syntheses of taxusin, taxinine and taxol via the novel selective boron-assisted migration reaction of 7-hydroxy-1-methoxybicyclo[2.2.2]-2-octenes. The proposed syntheses are general, thereby a number of analogs can be achieved. Each analog will be tested for antitumor activity using in vitro tissue culture systems. Once the active compounds are identified, they will be tested in vivo animal models.